VirOligo is a database of virus-specific oligonucleotides. The VirOligo database consists of two tables, Common data and Oligo data. The Oligo data table contains PCR primers and hybridization probes used for detection of viral nucleic acids and the Common data table contains the experimental conditions used in their detection. Each oligonucleotide entry contains links to PubMed, GenBank, NCBI Taxonomy databases and BLAST. As of July 2001, the VirOligo database contains a complete listing of oligonucleotides specific to viral agents associated with bovine respiratory disease that were published in English in peer-reviewed journals. The viruses are bovine herpes virus types 1, 3, 4 and 5, bovine viral diarrhea virus, bovine parainfluenza 3 virus, bovine respiratory syncytial virus, bovine adenovirus, bovine rhinovirus, bovine coronavirus, bovine reovirus, bovine enterovirus and alcelaphine herpesvirus-1. The VirOligo database is being expanded to other viruses and can be accessed through the Internet at http://viroligo.okstate.edu/.